Improvement in compositions for unhairing hides



UNITED STATES PATENT OFFICE.

ANDREW H. WARD, JR, or BOSTON, MASSAoHUSErrS, ASSIGNOR TO A. H. WARD, R,AND KIRK BOOTT.

IMPROVEMENT IN COMPOSITIONS FOR UNHAIRING HIDES.

Specification forming part of Letters Patent No. 12,151 dated January 2,1855.

To all whom it may concern:

Be it known that 1, ANDREW H. WARD, J r., of Boston, in the county ofSuffolk and State of Massachusetts, have invented a new and usefulimprovement in treating skins or hides, either previous to or during theprocess of tanning them and I do hereby declare that the sameis fullydescribed and represented in the following specification.

The nature of my invention consists in the employment of a solution ofcarbonate and sulphate of soda, into which the hide or skin is to besteeped, for the purpose of loosening its hair and preparing said hideor skin for the application of tannin to it.

In carrying out my invention I make use of about two pounds of thecarbonate of soda to one pound of the sulphate of soda, and fifteengallons or one hundredand twenty pounds (avoidupois) of liquid or water,not confining myself strictly to such proportions, as the same may besomewhat varied and Still be productive of good results.

The hide or skin with the hair on is to be steeped for about two days inthis solution. At the end of this time the hair may be removed from itby the usual process of beaming, the skin being left in a much betterstate for being tanned than when it is sweated or prepared with lime inthe usual way.

In using soda-ash and lime, which of late has been the practice withsome tanners in the preparation of skins for the reception of tannin,the skins have to be subjected to what is termed the drenching processin order to remove the lime. This drenching process con sists inimmersing them in a solution of guano, pigeons or hens dung, and it is avery offensive and disagreeable mode of treatment.

The employment of soda-ash and lime generally requires about three weekssoaking of a skin in order to properly prepare it. With my improved modeof treating the skin it is prepared for the beamster in about two days.By my improvement the drenching ofthe skins is entirely avoided. As soonas the hair has been removed, or the Skin hasbeen beamed, it should berinsed in clear water. It is then ready to be tanned. When the hair isremoved by the solution of the carbonate and sulphate of Soda, the hideis left in a puffed up state, and with its pores opened for thereception of the tanning material, into which it is next to be put.After the hide has absorbed as much of the tanning-liquor as itapparently can, it may be removed from the tan-vat and rinsed in water,in order to remove the material that clogs the pores, as they will befound to be more or less clogged with foreign matter. When sufficientlyrinsed the'skin may be again put into a solution of the depilatory saltsor carbonate and sulphate of soda, which will have the effect of puffing or swelling it and distending the pores. It may again be returned tothe tanning-vat, where it will absorb more of the tanning-liquor. Thisprocess may be repeated until thehide is thoroughly tanned.

By the employment of the solution of carbonate and sulphate of soda fordepilating a skin and preparing it for the reception of tannin it willbe better tanned in eight days than in the great length of time(generally Several months) that is usually consumed by the ordinaryprocess of liming, bathing, beaming, and tanning.

I have found that the use of carbonate of soda alone in depilating thehide is along and tedious operation, several weeks bein ,9; required toprepare the skin so that the hair maybe removed. By the addition ofsulphate of Soda to the carbonate in Solution a wonderful accelerationof the process is effected.

I shall not pretend .to state the rationale of the action of thehydrated compound solution;

but as experience and observation have exhibited a result of greatimportance in the use of this compound solution in the manner asdescribed, it is not necessary for me to go into chemical explanation ofthe manner in which the Solution of the carbonate and sulphate of Sodais made to operate so much more expeditiously on the skin than asolution of either the carbonate or sulphate alone.

The application'ofa compound solution of carbonate and sulphate of sodato hides and skins for the purpose of loosening their hair and preparingthem for the reception of tannin.

In testimony whereof I have hereunto set my signature this 20th day ofMay, A. D. 1854.

ANDREW I-I. WARD, JR.

